Aim: MBD Simulation on a Piston Assembly

Model all the parts and then assemble them in SolidWorks. The motion analysis is going to be carried out in three different conditions,

Sl.No	Wrist Pin Offset `	Crank Speed (Rpm)
1	"0" mm	2000
2	10 mm Positive	2000
3	10 mm Negative	2000

Introduction:-

The Piston Assembly Consist of mainly five parts such as Piston itself, Gudgeon pin, Connecting Rod, Endcap, and Crank. it is used in the different mechanical machines such as Internal/External combustion engines, compressors, pumps, and etc. based on Applications such as power-producing device (or) powerconsuming device it is used to transfer the power.

Parts Design:

• Piston: The piston is a component used is many mechanical machines piston transfers power from combusting fuel to the crank with the help of a connecting rod.

• Crank: The crank is used to convert linear motion into rotational motion and transfers the power to do work in a power-producing device and vice versa in a power consuming
  device.

• Wrist Pin: Wrist pin is used to connect the connecting rod and piston to transfer power.

• Connecting Rod : The connecting rod connects one side piston with another side crank and helps to convert linear motion into rotational motion of the crank.

• EndCap:- The Endcap is an extension of the connecting rod which helps to mount the connecting rod on the crank.

• Wrist Pin Offset:- The position of the wrist pin is going to be varied as followed. But the centre of the axis of the piston head and the crank are coincident to each other (i.e) They are on the same plane in all the three cases. To do Motion studies in all the three cases we are using crank axis as input to the motor with 2000 rpm. similarly, we are using 7200 frames per second and used precise contact option to get a more clear result.

1) 10 mm Positive Offset - If the crank rotation is in the Clockwise direction.

2) 10 mm Negative Offset - If the crank rotation is in the Clockwise direction.

• Assembly Of crank Piston Design:-

######Case-1 "0" mm Offset

######Case-2 "10" mm Positive Offset

######Case-3 "10" mm Negative Offset

Results & Graph:

• Crank_Piston_Assembly_0mm_offset

• Crank_Piston_Assembly_10mm_negative_offset

• Crank_Piston_Assembly_10mm_positive_offset

• Comparison Graph

Conclusion:-

• In all the above three plots of different cases, the linear displacement of the piston is nearly the same in all cases but the starting position, as well as the path at some duration, is different for each study which is due to the offset provided in the study. without offsetting the line of action of power transmission is caused impact load on the assembly which is harmful during operation.
• To get rid of this, offsetting the piston from crank so that the axis of the piston and connecting rod are aligned vertically at the moment of combustion - when the pressure in the cylinder is at its peak.
• Due to offset provided between the piston and crank the impact load is reduced. Doing this greatly reduces the stress acting on the connecting rod and friction from the diagonal force pushing the piston against the cylinder wall. At the same time, this enables more effective use of the energy produced by combustion which causes more efficient mechanism in real-life application.

Notes:- Please Visit the google drive link for part design and related files.

https://drive.google.com/drive/folders/13oy-rcYmwqXAE0WvhRgQsKIdUuNtoN73?usp=sharing